Back-center



UNITED STATES PATENT OFFICE.

A. LAFEVER AND GEORGE C. BARNES, OF BATTLE CREEK, MICHIGAN.

BACK-CENTER FOR LATHES.

Specification of Letters Patent No.

To all whom it may concern:

Be it known that we, A. LaiiEvER and GEORGE C. BARNES, both of Battle Creek, in the county of Calhoun and State of Michigan, have invented a new and Improved Back-Center for Turning-Lathes; and we do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, forming a part of this specilication, in which- Figure 1 represents a longitudinal central section, taken through the back center bar showing our device for feeding oil to the point of the center pin making it a self-oiling back center. Fig. 2 is a top view of the back center.

Similar letters of reference indicate corresponding parts in both figures. l

The object of our invention is to save time and oil in oiling the back center or back support for the work to be turned in the lathe. The usual manner of doing this is to provide a receptacle for oil hung in a handy situation for the turner with a feather or spoon, which is used very frequently in turning elaborate work, and consequently much time and oil is expended, from the fact that the center point is oiled profusely, and the oil is either absorbed by the wood or thrown off by its centrifugal action. Our invention effectually obviates these evils and supplies only a suflicient quantity of oil to lubricate the point of the center, and this is effectually done without the attention of the workman, it being a self-oiling center.

Our invention consists in oiling the center point, or that point against which the wood to be turned abuts by causing the oil to flow from an oil cup through t-he end of the shank, and to the point of a valve stem, which, when not in use, will prevent the oil contained i`n the oil cup from fiowing out; and it further consists in tapping the valve stem in the front end of the shank by a screw cap so that the self-oiler may be applied to old Shanks by removing the old center points therefrom, as hereinafter described.

The front end of the stock or shank, A, is drilled out as shown by Fig. 1, forming a recess or hole, the length and diameter of 26,998, dated January 31, 1860.

which shall be suiiicient to admit the valve stem, b, and a helical spring, o, which latter acts against a shoulder formed in the shank, A, by drilling a smaller hole, d, of a size only to admit the valve stem, l), and also against the back end of a conical enlargement, e, on said stem, which enlargement acts as a valve against its seat in a screw cap, D, and prevents the oil from cup, E, from escaping through the center of the screw cap, D, except when the valve stem is forced back into the hole, (Z. The spring, c, keeps the valve, c, closely in its seat when the pressure is relieved from the point of the center pin.

The cap, D, or end of the shank, A, has a female screw thread tapped in its end so that the new centers can be readily attached to old shanks, and thus save expense.

The oil cup, E, has a communication through its stem with the valve stem, b, and keeps the recess, s, in the end of the stock constantly charged with oil, which, during the operation of turning, escapes through the end of cap, D, and lubricates the point of the stem, 2),' the side of the stem, l), in front of the valve, e, is slightly grooved for permitting the oil to iow freely over its surface from the recess, s.

It will now be seen from the above description that in putting the wood or stick to be turned in the lathe the projecting end of the valve stem, Z), is slightly pressed back and the oil from the cup, E, will gradually flow to the end of the stick and keep it constantly lubricated. When the operation is completed, and the stick removed, the valve, e, will be forced against its seat by the spring, c, and thus stop the flow of oil.

Having thus described our invention what we claim and desire to secure by Letters Patent, is:--

The valve stem, b, spring, c, and cap, D, applied to the stock or shank, A, essentially as set forth, arranged and operating so as to feed oil from a cup or other suitable receptacle to the object to be turned.

A. LAFEVER. GEO. C. BARNES. Witnesses:

C. A. WHEELER, LUTHER ALDs. 

